[CT and MRT of the paranasal sinuses]

The updated minimally invasive surgical methods used in chronic sinusitis require accurate and anatomically detailed preoperative diagnostics. Conventional x-rays cannot satisfy these increasing diagnostic requirement, since this method images a complex three-dimensional anatomy and pathology by means of a two-dimensional summation take. Both CT and MRI have a high resolution of contrast and site and assure visualization that is free from superimpositions. Both methods, however, differ from one another in respect to principles of technique and in characteristics; in this regard, the imaging of bone by MRI is always hypointense, which is a major drawback. Hence, for clarifying the identification of chronic sinusitides, in the diagnosis of suspected chronic sinusitis, CT is the method of choice. Besides the typical presentation of normal anatomy and anatomical variations, pathological findings are demonstrated.